NEW YORK » Unbeknownst to most customers, AT&T Inc. has fired up a new wireless data network in five cities in the last few months, offering roughly double the speeds of its older network for a handful of devices.

On Sunday, the phone company will start marketing the network in Atlanta, Chicago, Dallas, Houston and San Antonio. It won't be selling a new data plan — use of the new "4G LTE" network will be a perk thrown in with existing plans, AT&T Inc. network architecture and planning executive Kris Rinne said Friday.

Rinne said the network will provide downloads speeds of 5 megabits to 12 megabits per second. That's enough to download a DVD-quality two-hour movie in 15 minutes. It's in line with the speeds on Verizon's LTE network, which launched late last year with separate data plans. AT&T's older "4G" network provides top download speeds around 6 megabits per second.

Upload speeds on the LTE network are also significantly higher than on regular "4G," clocking in at 2 megabits to 5 megabits per second, Rinne said. That's fast enough to send one minute of high-definition video from a tablet to Facebook in three minutes.

The LTE-capable devices AT&T sells are a tablet — the HTC Jetstream — two USB data sticks and a "mobile Wi-Fi hotspot." They're sold with the standard AT&T non-phone data plan, which provides 5 gigabytes of data for $50 per month, except for the tablet, which comes with a $35 plan with 3 gigabytes of data.

At top LTE download speeds, it takes about an hour to exhaust the monthly allotment of 5 gigabytes. Like Verizon, AT&T charges $10 per gigabyte used above that.

Rinne said the company will have an LTE-capable phone by the end of the year.

Analysts don't expect the next iPhone to be LTE-capable at its launch, which they think could be within a month. Apple Inc. and AT&T haven't said when the phone will launch or if it will be LTE-capable.

AT&T plans to light up the LTE network in ten more cities by the end of the year, but hasn't said which ones.

AT&T's LTE plans have figured in the company's bid to buy T-Mobile USA for $39 billion. AT&T says it originally planned to build out LTE to cover 80 percent of the U.S. population, but if regulators let it buy T-Mobile, it will upgrade cell sites in rural areas as well, to cover 97 percent of the population. AT&T has less radio spectrum available for LTE than Verizon does, so it wants to take some of the spectrum T-Mobile uses for 3G and convert it to LTE.

The initial five LTE cities are all areas in which AT&T is the landline phone company. That makes it easier for the company to provide the LTE-enabled cell towers with high-speed wired connections to the Internet. The company's headquarters is in Dallas, one of the launch cities.